Dark Matter Annihilation Can Produce a Detectable Antihelium Flux through Λ[over ¯]_{b} Decays

Area of Science:

• Particle Physics
• Cosmic Ray Physics
• Astrophysics

Background:

• The Alpha Magnetic Spectrometer (AMS-02) has tentatively detected cosmic-ray antihelium events.
• Astrophysical production of antihelium is considered negligible, making these events potential indicators of new physics.
• Dark matter-induced antihelium flux is typically predicted to be below current detection sensitivities.

Purpose of the Study:

• To investigate a previously overlooked Standard Model process that could enhance the antihelium flux.
• To determine if this process can explain the observed antihelium events and reconcile them with dark matter theories.
• To re-evaluate the potential for detecting dark matter signals through antihelium production.

Main Methods:

• Theoretical modeling of particle interactions within the Standard Model.
• Simulations of antihelium production via the decay of Lambda-b baryons.
• Comparison of predicted antihelium fluxes with AMS-02 observational data and antiproton constraints.

Main Results:

• The decay of Lambda-b baryons is identified as a significant source of antihelium production.
• This Standard Model process can increase the antihelium flux by up to two orders of magnitude.
• The boosted antihelium flux is potentially detectable by AMS-02 and could be misinterpreted as a dark matter signal.

Conclusions:

• The production of antihelium via Lambda-b decays can significantly enhance the flux observed by AMS-02.
• This process may explain the tentative antihelium detections without invoking new physics.
• Further investigation is needed to disentangle Standard Model contributions from potential dark matter signals in cosmic-ray antihelium observations.